How should I stack his overpair? My hand is faceup..
Flop raise wouldnt rep much, but never bluffing this board.
Raise turn to 12? I could do that with sth like 56s, fd, 89s.. This way I could stack him. I think he is not betting this turn with air.

With your history I think you should raise turn. Since you bluffraised him before then he would very likely not fold his overpairs, so I think he would b/c 12$ raise to then decide on the river.
River shove seems very strong and I think he would fold his overpairs- I´d raise to 25$ to give him option call also his overpairs.